Benefits of inulin and fructo-oligosaccharides on high fat diet-induced type 2 diabetes mellitus by regulating the gut microbiota in mice.

Type 2 diabetes mellitus (T2DM) is pathologically associated with gut microbiota imbalance, which is implicated in disease progression through metabolic and inflammatory pathways. The therapeutic potential of inulin, a well-characterized prebiotic, has been explored to mitigate T2DM via microbiota modulation. However, the efficacy of this intervention, with its performance dependent on the degree of polymerization (DP), requires further investigation. This study assessed the therapeutic roles of inulin (DP3-60) and fructo-oligosaccharides (FOS, DP3-10) in T2DM management. Dietary administration of these prebiotic compounds demonstrated a significant capacity to alleviate multiple metabolic pathologies, including obesity, insulin resistance, systemic inflammation, oxidative stress, dyslipidemia and hepatic steatosis in high-fat diet (HFD)-fed induced T2DM mice. Significant superior efficacy was observed in FOS for ameliorating glucose metabolic dysregulation, adipocyte hypertrophy, liver weight, and histopathological alterations in colonic tissue, while inulin exhibited greater potency in alleviating oxidative stress. Both inulin and FOS enhanced gut microbiota diversity and richness in T2DM mice, accompanied by a significant reduction in Firmicutes/Bacteroidetes ratio. Notably, the S24-7 family emerged as a crucial microbial taxon modulated by both inulin and FOS. Furthermore, FOS demonstrated superior capacity to restore HFD-induced gut microbiota. Taxonomically significant amplicon sequence variants (ASVs), which were altered by HFD and modulated by inulin and FOS, exhibited distinct taxonomic profiles between the two compounds. This study provides preliminary evidence that the biological effects and beneficial properties of inulin-type fructans exhibit DP-dependent variations, which may enhance their efficient utilization in metabolic disorders.